Methodology
Fee assumptions
How What Profit models UK marketplace fees — and what we intentionally leave out.
The calculator is a decision aid, not an invoice. Category rates, promotions, account types, and VAT treatment change. Always confirm live rates on the platform before you scale.
What we include
- Typical platform / referral / processing fees by channel
- Optional VAT on platform fees (common for UK VAT-registered businesses)
- Optional remittance of sales VAT from the sale total
- Promoted listings / ads as a % of sale
- Expected return rate affecting take-home
- Buyer-charged postage vs your shipping cost
- Amazon FBA fulfilment as an editable estimate
What we leave out (unless you add it)
- Monthly SaaS plans (e.g. Shopify subscription)
- Offsite ads programmes with separate billing
- Storage, long-term, and removal fees
- Creator commissions beyond a simple ads % proxy
- Currency conversion and international duties